how cryostorage is supposed to protect embryos like those possibly damaged at 2 fertility clinics - stainless steel food thermos
When two different birth centers (
In Ohio and San Francisco)
Having problems keeping embryos and eggs frozen at the right temperature, the first thing to think of is a power outage, something that affects the home refrigerator.
However, there is a big difference between freezing and storage in the laboratory, and what is stored is an integral part of family fertility.
How frozen storage works.
It is very helpful to understand how low temperature storage works and why such problems occur.
Low temperature does not depend on electricity at all;
It depends on liquid nitrogen.
Nitrogen is a gas at room temperature (
In fact, this is most of the air we breathe).
But when you cool it to minus zero
Become liquid at 320 degrees F;
Extremely cold liquidAs Dr.
Rick Paulson, former chairman of the American Society of Reproductive Medicine, told us, "the freezer is best considered a huge thermos.
They are made of stainless steel, cylindrical, thick insulating material on the walls and bottom, and thick insulating covers.
They are filled with liquid nitrogen.
"Tanks stand at a height around the waist, and the cells they store are sealed inside the tank.
"All eggs, sperm and embryos are submerged in liquid nitrogen," Paulson said . ".
"If the temperature on the surface of the liquid rises, liquid nitrogen will start boiling [into gas]
The temperature of the remaining liquid will remain at a very low temperature at the boiling point until it disappears.
There is no such thing as warm water liquid nitrogen.
"Even if the lid is closed, a little bit of liquid nitrogen will evaporate on the surface of the liquid at a rate of about inches per day.
It is therefore constantly supplemented.
Paulson, now director of reproductive endocrine and infertility at the University of Southern California, Los Angeles Keck Medicine, explained the process: "Our tanks have automatic replenishment.
They are constantly being monitored.
In order to double check the equipment, the liquid nitrogen level is checked every day.
Even if all the monitoring and automatic filling equipment fails at the same time, there will be no bad situation in the stored eggs and embryos for at least two weeks, and of course, we are monitoring them every day.
"This is a problem for fertility experts-even if a tank is on, it will take more than two weeks for all nitrogen to evaporate-any cell that is still covered with nitrogen remains below negative --320 degrees.
So, how does the water tanks in two different birth centers produce temperature fluctuations that can damage cells?